Chempak No.4 – High potash fertiliser

Why use this product?

Eucalyptus grow extremely quickly, throwing out masses of foliage and branchlets with gay abandon, well into the later summer.

Their new seasons growth can be quite floppy early on; they sort of forget to lay down scaffolding in their trunk and branches as they grow.

In the nursery, we find that they don’t really lignify (firm up) until November, often after the first frosts and this late tender growth can get scorched.

This is of particular concern if you are growing for cut foliage, but also a problem for young trees attempting to develop sturdy trunks.

A readily available source of soluble potassium helps do many things for your Euc. It helps towards protecting against frost damage by encouraging your tree to produce and ripen (harden) woody material.

Chempak No.4 – High potash fertiliser

Chempak No. 4 is a highly soluble, balanced plant food containing some Nitrogen and Phosphorus, but high in Potassium along with 7 trace elements, far more than ordinary fertilisers.

Think plant equivalent of baked beans on toast with added vitamin pills!

Nitrogen is the nutrient most associated with leafy foliage (think lettuce), but is also important to sustain growth. Eucalypts love nitrogen, but like crack cocaine – it makes them euphoric, sick and then they fall over!  Use it sparingly.

Nitrogen administered late in the summer can also result in loss of hardiness, and generally suppress flower bud development.

N can be found in high quantities in organic fertilisers and manures.

In the presence of a great deal of Nitrogen, Eucalyptus will produce a metaphorical skyscraper with poor foundations. Hold the N!

Phosphorus is associated with developing the root system.

Although it can also support many metabolic functions with in plants generally, Eucalyptus have evolved in a land fairly devoid of the mineral and therefore, don’t require very much of it.

Potassium is an amazing mineral, performing many duties within a plant. It regulates the flow of water. It is the first aid kit and called upon when there is a wound, pest or disease.

In Eucalypts, it is very important for providing sturdy woody growth and works with sulphur to help the Euc lay down woody fibre and ripen wood going into Autumn; protecting against frost damage.

Time of year to apply: any time from April through to September is good, but especially good during August and September

Potassium is a very soluble salt that washes away from your soil very quickly. It needs replenishing on a regular basis.  A little and often is best rather than a big dose in one go as surplus will leach out into ground water. This is wasteful and not great for the environment.  Sandy and stony soils are often deficient in potassium, because they are so free draining.

How to use:

Feed Chempak No.4 regularly to your potted Eucalyptus trees from Spring through to end of Summer. You can feed up to once every 14 days. Read more about growing Eucalyptus in containers here

Dosage and Rate of Use: 2 level measures of Chempak crystals in 5 litres (about 1 gallon) of water.  If growing in the ground for cut foliage, apply Chempak No.4 once a month, in season, during the first 2-3 years of planting in your garden. If growing in a container, feed your potted Eucalyptus once every 2 weeks, during the growing season.

For trees growing in the ground:

Take a look at our slow release, (long chain molecule) Eucalyptus Smart Fertiliser here.  It works with the Rootgrow mycorrhizal fungi, which turn the Smart Fertiliser into ‘soup’ which they feed into the roots of your Eucalyptus tree. Please note that we do not recommend Eucalyptus Smart Fertiliser for plants growing in pots and containers.